Maximum Size of a Wooden Sailing Vessel

Question

King Darien "Stubby" Shortstock, the incredibly petite king of 1600s Imperial Rathakos, has commissioned me to build him a massive flagship to lead his mighty fleet. He wants it big. Bigger than any other vessel ever built, and then some. And then more.

Is there a maximum size to a wooden sailing vessel, beyond which it could not function, due to either lack of wind, the way in which it interacts with the water, etc? I'm aware that the larger it becomes, the more draft it would have, and the King insists I avoid it simply being a massive flat bottomed barge. I am currently considering some sort of design where is has multiple rows of masts, to maximize exposure to the wind. It will only be driven by wind or muscle power, in the form of oars or hand cranked wheels.

If possible, I would like to have a sailing vessel the size of a modern aircraft carrier. Speed is not a priority, simply being huge, carrying massive amounts of cannon and even mortars for LONG range engagements, and being able to move under wind and oar power will satisfy my King's desires. It need not be able to approach port, as we can have other vessels travel with it to ferry men in and out, and its undoubtedly massive draft is not a problem, as my King plans to use slave labor to dig a harbor as deep as is necessary.

I'm trying to figure out if there is an analogue to the "square cube law" for biological organisms when it comes to a ship like this, whether it eventually simply would collapse under its own size when built as a primarily wooden sailing vessel, or if it's simply impractical due to cost. My king has an absurd amount of money, so the cost isn't an obstacle.

It is very important to note that my king wants this flagship not for any sort of compensation for his own size and ego, but simply wants the biggest ship possible, regardless of combat efficacy. His Generals have mentioned that they would like to use it to mount massive mortars that can outrange any normal vessel's cannons, allowing them to have a sort of "over the horizon" firing capability directed by other ships signaling where to fire, but that is simply a bonus. They aren't the ones who can have me executed if I fail.

(There were a couple of other questions on the site that were somewhat similar to what I am looking for, but both differed enough that they couldn't quite answer my question specifically regarding the maximum size of a wooden sailing vessel, built in the 1600s, still moving under wind or muscle power)

Answer 1

There are several problems to deal with in building a really big wooden ship in the 1600s. The biggest one of these is lack of a solid body of engineering and scientific knowledge. Which is really important, given that stability and lateral stresses on the hull are the critical limits on how big a ship can be made that will not capsize 1,300 m into its maiden voyage like the Vasa in 1628 (yes, that is metres, not kilometres!) or capsize in its first storm like HMS Captain in 1870 (see another account here) in which all but 18 of a crew of almost 500 were lost. It was only after the latter disaster that calculating the stability of a vessel became a more scientifically rigorous process.

Note that both of these ships appear in the List of large sailing vessels, in which it is noteworthy that the first wooden-hulled vessel with a length over 100 m was the Great Republic, which was launched in 1853. While Great Republic did have a wooden hull, the Industrial Revolution was in full swing by this point and the ship included 336.5 tons of iron and 56 tons of copper - probably not feasible to obtain for a ship in the 1600s, in addition to requiring another 250 years' knowledge of building and manufacturing techniques.

Even if the naval architect manages to design a ship of unprecedented size that will not capsize or spring leaks in the course of its first voyage, there is the issue of building and launching it in the first place. Given the engineering knowledge and materials available, there is a limit to how big a ship can be built that can subsequently be floated. Drydock technology did exist by the start of the 16th century, but the techniques for closing and opening docks were fairly primitive, providing a practical upper limit on the size of ships that could be built.

Summing up, I would suggest that building a ship longer than 70-80 metres in the 1600s is practically impossible, even with an unlimited budget for building a huge drydock and assuming the architect knows all the tricks to build a sufficiently stable ship. The techniques and resources to build the metal components to connect and reinforce a larger wooden hull simply did not exist. (@causative is correct that the Wyoming was much larger, but note that it was launched in 1909, taking advantage of another 300 years of engineering and technological development.)

Answer 2

Nautical experts generally believe that there is a severe limit to the size of wooden sailing ships.

Here is a link to Wikipedia's list of the largest sailing ships of all time:

https://en.wikipedia.org/wiki/List_of_large_sailing_vessels

Some of them were steamships with masts and sails for propulsion in case the engines, failed, and others were or are sailing ships with engines to use when there is no wind. And some were pure sailing ships.

Judging by the sizes of the ships on the list, it might be possible to build sailing ships a thousand feet long or longer which sailed well under sail.

The bad news is that all the longest ships on the list were made out of iron or steel.

The list of the longest wooden ships ever built has much shorter ships. All of the longest wooden ships had structural problems, even though most of them had iron or steel structural parts to strengthen them.

https://en.wikipedia.org/wiki/List_of_longest_wooden_ships

So if you want to make a thousand foot long wooden flagship to dwarf the 150 or 200 foot long ships of the line, you have a problem.

The list of very large wooden ships which are claimed but poorly documented is interesting.

https://en.wikipedia.org/wiki/List_of_longest_wooden_ships#Claimed_but_poorly_documented

If some of the largest on that lists were real, the builders should have found some ways to overcome the limitations of wooden ships which seem insurmountable to modern people.

One thing that you could do would be to reduce rough weather in the waters where your supersized ship operates to ease strain on the wooden hull.

I note that the Great Lakes are large enough to have fierce storms and giant waves. So perhaps the fleets operate in a group of large lakes which ae all connected, and all large enough for even the largest ships to maneuver in, but which are not large enough for the winds to build up large waves before the waves reach the shore.

Perhaps the lakes are all long from north to south and the winds blow from west to east, for example.

Or maybe the naval battles are planned to be fought in a long but narrow strait without room for large waves to form.

Some some very large wooden ships were allegedly use in naval battles in Chinese lakes and rivers.

The length of ships is usually measured by the length on deck, the topmost deck going from bow to stern. Another measurement, the length overall, is the total length of the ship including poles extending from the hull.

And the length of a bowsprit sometimes approached 100 feet.

Some old sailing ships had a platform on the bowsprit with a mast and sail, thus adding another mast to the ship and extending the length of the sails. It was called a sprit topmast.

https://en.wikipedia.org/wiki/Sprit_topmast

https://en.wikipedia.org/wiki/Spritsail_%28square-rigged%29#/media/File:De_BATAVIA_voor_de_film_onderweg_als_de_NIEUW_HOORN_(03).jpg

https://www.modelshipsinthecinema.com/2015/10/the-spanish-main-1945.html

And this depiction of the English royal carrick Henry Grace a Dieu shows it with what could be called a "sternsprit", though it isn't as long as the bowsprit.

https://en.wikipedia.org/wiki/Henry_Grace_%C3%A0_Dieu#/media/File:AnthonyRoll-1_Great_Harry.jpg

So naturally I can imagine a ship which has a platform, a mast, and a sail on such a "sternsprit" as well as on the bowsprit. I think that such a ship would be very impressive looking.

And possibly a super ship could extend its width with "sidesprits" with platforms, sails and masts.

There are claims that the allegedly gigantic largest Junks in Cheng He's fleets had two rows of masts in a zig-zag pattern, so you are not the first to think of having more than one row of masts.

The vessel which allegedly had the most masts was probably a raft built by Roman solders during the Republic to escape from Sardinia or Corsica. From what I remember it supposedly had dozens of masts and sails. So it probably had more than one row of masts. Since those Romans were not expert shipwrights, it broke apart at sea.

You say your shop should be propelled by sails or

muscle power, in the form of oars or hand cranked wheels.

Hand cranks are probably not the best methods, since men's legs are stronger than their arms. That is why there are little boats powered by bicycle like foot pedals instead of hand cranks. You might want to consider large wheels, like those used to pull up anchors, turned by men or draft animals, as the power source for paddle wheels or propellers.

Or you might want to use treadmills to power the paddlewheels, as on Chinese paddlewheel vessels.

I note that some types of sails are rigged so that they can swivel and change their orientation, to take advantage of changing wind directions. And it is possible that some of those sails had booms almost a hundred feet long. And if their masts were near the sides of a ship instead of the centerline, they could extend far beyond the sides of the ship, and thus make the ship much wider if booms are counted.

There is speculation that some allegedly giant ancient wooden ships were catamarans, with two hulls side by side.

During the 1850s a ship was built called the connector with separate hulls from front to back, connected by giant hinges.

https://www.shippingwondersoftheworld.com/novelties.html

So maybe your super wooden flagship could have three to five sections, for example, each 150 to 300 feet long, and thus a total length of 450 to 1,500 feet, not counting the hinged spaces between the hulls.

And possibly you might want to consider having several connected hulls side by side and front to back.

And these are some suggestions for trying to overcome some of the problems with building super large wooden ships.

Answer 3

They built Belanya by the end of the 1600's. These were giant wooden ships that were built for transporting wood down the Volga, and were dismantled for their wood then they arrived. These would not make elegant sailing ships but they would make a good gun platform. maybe it could be towed by sailing ships.

A giant ship will be at risk of cracking when it meets long waves at sea and the buoyancy is not applied evenly. If you could make your ship in sections that can float separately, you could divide your giant ship into sections connected by ropes when a storm was expected, and pull it back together when the storm had passed.

PS:

See also Disposable Ship. Ships that were dismantled and sold for wood were exempt from a high UK tax on imported timber. The 'Columbus' (mentioned elsewhere) was one of these ships. it had a square, boxy design, but having made it across the Atlantic, the owners decided to try fetching a second cargo, and it broke. The 'Baron of Renfrew' was another: that made as far as the Godwin Sands before it broke. If the largest ones were designed for a single journey, this does not necessarily mean large sailing ships always break.

Wood ship design suffered from two faults: ignorance of fatigue in wood, and the temptation to add an extra bit in the middle so it carried more. This gave you long-thin pencils that snapped in heavy seas. You could probably make a bigger, wider wooden ship, but nobody did.

Answer 4

The biggest wooden sailing ship ever made was the Wyoming which was 450ft long, or half the length of a Nimitz-class aircraft carrier (and 10% of the tonnage). It apparently sailed well enough. The major problem was that the wood was not strong enough to withstand heavy seas in such a long ship, causing it to flex and let water in. After 15 years of service the ship sank in heavy seas, possibly again due to the weakness of the wood.

Perhaps you could just build your craft stronger than the Wyoming - wider, with thicker beams of a higher quality. Or maybe you are sailing it on a particularly calm sea that very rarely gets severe storms.

Perhaps the king wouldn't object to a huge steel chain, running from bow to stern to put the hull under compression for added stiffness.

Note also that the Wyoming used steam engines to operate her vast sails and pump out the water. Perhaps muscle power could do the same if your setting lacks steam engines, but you'd need a much larger crew.

Answer 5

It's important to distinguish between what is the largest possible and the largest practical. Putting practical issues aside for one moment it should be possible to build a wooden ship of almost any length in a dead flat calm water with an unlimited supply of resources. Just join one vessel to another daisy chain fashion with big beams. It would be possible to even have two such daisy chain strings in parallel and build a platform between the two.

BUT obviously such arrangements aren’t practical. And there are a wide range of factors that would make such a vessel impractical. In no particular order some of the problems are:

There are limits to resources. There are limits on the amount of money available to pay people, the number of slaves available and food to feed everyone. There are limits on the time of construction (wood rots in water eventually).

The weather would soon wreck a vast ship in anything except a dead flat calm. Any mild swell would put a huge strain on the ship and break it up. Tides, currents and winds could also present irresistible forces that could destroy the ship by various means.

To a limited extent technology would help, but in the 1600’s the technology available would best be described as rudimentary and totally inadequate.

Your question doesn't have a definitive answer. As ships get bigger they become less practical and at 80-100m long the practical problems start to outweigh any the advantages for building it in the first place.And the chance of finishing it or using it before it is destroyed by the elements increases.